Maternal Death Due to Amniotic Fluid Embolism: A National Study in France

A structured definition of amniotic fluid embolism (AFE) based on 4 criteria was recently proposed for use in research by the Society for Maternal-Fetal Medicine (SMFM) and the Amniotic Fluid Embolism Foundation. The main objective of this study was to review all AFE-related maternal deaths in France during 2007-2011 according to the presence or not of all these 4 diagnostic criteria.

Maternal deaths due to AFE were identified by the national experts committee of the French Confidential Enquiry into Maternal Deaths during 2007-2011 (n = 39). The maternal mortality ratio for AFE was calculated. We applied the structured definition proposed by the Society for Maternal-Fetal Medicine and the Amniotic Fluid Embolism Foundation to AFE-related maternal deaths identified by the national experts committee. Characteristics of women, pregnancies and deliveries; clinical and biological features of AFE; and specific laboratory tests used were described by the presence or not of all 4 diagnostic criteria. Management of obstetric hemorrhage and quality of care according to the experts were also described.

The maternal mortality ratio from AFE was 0.95/100,000 live births (95% confidence interval, 0.67-1.3). Detailed clinical data were collected for 36 women who died from AFE: 21 (58%) had all 4 proposed diagnostic criteria and 15 (42%) had 1 or more missing criterion. Documented early disseminated intravascular coagulopathy was missing for 14 women, and 2 women exhibited more than 1 missing criterion. Ten of the 15 women with missing criteria had clinical coagulopathy, with standard hemostasis tests performed in only 3. Specific diagnostic examinations for AFE were performed in similar proportions by the presence or not of all diagnostic criteria. Opportunities to improve care included timely performance of indicated hysterectomy (n = 13) and improved transfusion practices (n = 9). In the context of maternal cardiac arrest, for 5 of 13 women, fetal extraction was performed within 5 minutes.

The structured definition of AFE for research studies would exclude more than one-third of AFE-related maternal deaths identified by the national experts committee. Inclusion of clinical coagulopathy as a diagnostic criterion for AFE would reduce this proportion to 14%. There is still room for improvement in the management of obstetric hemorrhage and timely fetal extraction in the context of maternal cardiac arrest, frequently observed in AFE-related maternal death.